code: def testEmpty(self):
      self.assertComputeFails(WarpedAutoCorrelation(maxLag=1), [])
  
file_path: essentia/test/src/unittests/stats/test_warpedautocorrelation.py
imports: from essentia_test import *
label_desc: Use image node_id 4 for calling the TestWarpedAutoCorrelation obj's underlying member method code with example usage: obj.testEmpty() without return types